Theoretical Investigation of the Mechanism of Rh(III)-catalyzed Annulation of 2-Biphenylboronic Acid with Activated Alkene

The mechanism is investigated for Cp^tBuRh(OH)₂-catalyzed annulation of 2-biphenylboronic acid with three activated alkenes using M06-2X functional. The reaction comprises transmetalation via two steps and following C-H activation producing reactive Rh-biphenyl complex with two Rh—C σ bonds. After the coordination/insertion of alkenes, respective fused or bridged cyclic products are yielded depending on different alkenes accompanied by the release of Cp^tBuRh. The promotion of Cp^tBuRh(OH)₂ lies in the barrier decrease of transmetalation and C-H activation ready for coordination/insertion ensuring the smooth progress of common rate-limiting reductive elimination. The stereoselective transfer and ring rotation are specific for benzoquinone and cyclopropenone. The role of Rh(III) catalyst and release of Rh(I) is supported by Multiwfn analysis on frontier molecular orbital(FMO) of specific transiton states(TSs) and Mayer bond order(MBO) value of vital bonding, breaking.     

1a,3-二苯基-1,1,4,4-四氯-1a,2,3,4-四氢-1H-吖丙啶并[2,1-e][1,6]苯并硫氮杂辛因的合成及晶体结构

苯并杂类化合物为常用镇静剂及治疗心血管疾病和抗病毒的药物［１～３］,苯并杂与五六元杂环并合形成的三环化合物也是重要的药用杂环化合物,如１,４－苯并二氮杂与１,２,４－三唑并合形成的三环化合物为常用的治疗中枢神经系统疾病药物［４］．而吖丙啶与１,...     

First Total Synthesis of (-)-4-O-(6'-Hydroxy-7'(9')-Dehydro-6',7,-Dihydrogeranyl)-Coniferyl Alcohol

Some Ligularia species have long used as folk remedies due to their antibiotic, antiphlogistic and antitumor activities.¹ Compound 1,² a novel coniferyl alcohol, was isolated from ligularia duciformis(Compoitae). The geometrical structure of 1,determined by spectroscopic techniques, was corresponded to 4-o-(6,-hydroxy-7'(9')-dehydro-6',7'-dihydrogeranyl)-coniferyl alcohol. But its absolute configuration at C-₆,has not yet been determined. Herein, we report the total synthesis of (6'S)-(-)-1 from Geraniol 2 through 9 steps (Scheme 1).     

磺化酞菁镓的二聚现象研究

采用分光光度法研究了磺化酞菁镓的二聚现象;测定了二聚常数k_d,讨论了PH值、离子强度、水、温度等因素对k_d的影响,研究结果表明:磺化酞菁镓的二聚反应可表示成:2SPcGaOH⇔(SPcGa)₂O+H₂O 且磺化酞菁镓的二聚常数随着离子强度、磺酸基数目、水的浓度的增加而增加。     

气液色谱法研究二元混合固定液的无限稀活度系数

用气液色谱法测定若干烃类溶质在二元混合固定液中的无限稀活度系数,所研究的二元混合液为具有不同极性的四种类型:(1)正廿二烷-正十六烷;(2)邻苯二甲酸二壬酯-角鲨烷;(3)环丁砜-碳酸丙烯酯;(4)环丁砜-己二腈。用最小二乘法拟合三元系的Flory-Huggins公式,得到各种相互作用参数。     

三硼酸铯和硼酸铯锂晶体的晶格振动光谱研究

本文对新型非线性光学晶体三硼酸铯（ＣｓＢ３Ｏ５∶ＣＢＯ）和硼酸铯锂（ＣｓＬｉＢ６Ｏ１０∶ＣＬＢＯ）进行了晶格振动光谱研究。首先对两种晶体的基本晶格振动模进行了对称性分类,记录了两种晶体低温下的拉曼光谱和室温下的红外反射光谱,对晶体的晶格振动模进行了认定,将振动模归属于平面六元环（Ｂ３Ｏ６）和四面体（ＢＯ４）。然后比较了ＣＢＯ,ＣＬＢＯ和ＬＢＯ（ＬｉＢ３Ｏ５）三种晶体的晶格振动光谱,讨论了阳离子对振动光谱的影响。另外,还讨论了硼酸盐晶体晶格振动模ＬＯ ＴＯ分裂的大小与晶体非线性光学系数之间的关系。     

基于线性规划核心矩阵的单纯形算法

本文讨论了线性规划中的核心矩阵及其特性,探讨了利用核心矩阵实现单纯形算法的可能性,并进一步提出了一个基于核心矩阵的两阶段原始一对偶单纯形方法,该方法通过原始和对偶两个阶段的迭代,可以在有限次迭代中收敛到原问题的最优解或证明问题无解或无界．在试验的22个问题中,该算法的计算效率总体优于基于传统单纯形方法的MINOS软件．     

苝四羧酸多联体化合物的合成及其光谱特性研究

本文合成了8个 四羧酸多联体化合物;测定了这些化合物的吸收光谱、荧光光谱。研究了由供电子分子键连的多联体分子的光谱特性及其分子体系内稳态荧光猝灭机理。首次从吸收光谱和荧光光谱上分析和考察了四羧酸多联体化合物分子体系内的光致电子转移反应。